RESUMEN
PURPOSE: To evaluate long-term change in functional and structural outcomes after successful repair of large macular holes (MH) with internal limiting membrane (ILM) flap techniques. METHODS: Eleven consecutive patients were reviewed over a 1-year time period after the successful repair of large MH with ILM flap techniques. SD-optical coherence tomography (SD-OCT) images were taken to assess the anatomical outcome after surgery, while the best-corrected visual acuity (BCVA) was tested using Snellen charts to evaluate the functional outcome. Each patient was evaluated at 1, 6 and 12 months after surgery, respectively. RESULTS: All cases achieved complete anatomical closure. All patients showed a microstructural regeneration of the retina with a decrease in ellipsoid zone defects over the 1-year follow-up. Functionally, as compared to baseline, all of the patients showed improvements in best-corrected visual acuity of 1-4 lines at the final examination after 12 months post-operatively. CONCLUSIONS: Long-term results show further improvement in the best-corrected visual acuity as well as further microstructural regeneration of the retina and decrease in ellipsoid zone defects over time. The exact mechanism, which promotes closure of the macular hole and reconstruction of the ellipsoid zone after internal Limiting Membrane autograft surgery, still remains unknown.
Asunto(s)
Membrana Basal/trasplante , Perforaciones de la Retina/cirugía , Vitrectomía/métodos , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Retina/patología , Perforaciones de la Retina/patología , Perforaciones de la Retina/fisiopatología , Colgajos Quirúrgicos , Agudeza Visual/fisiologíaRESUMEN
PURPOSE: To evaluate the technique and the long-term outcomes after autologous internal limiting membrane flap surgery for refractory macular holes. METHODS: The free ILM flap technique was used as a secondary procedure for non-closing macular holes after failed initial standard procedure. SD-OCT images were taken to assess the anatomical outcome of surgery while best corrected visual acuity (BCVA) was used to evaluate the functional outcome during a one-year follow-up. RESULTS: A total of five eyes were included. All patients underwent successful intended manipulation of the ILM flap. All cases achieved complete anatomical closure. Partial microstructural reconstruction was demonstrated on SD-OCT as restoration of the external limiting membrane and the ellipsoid zone and was observed in all cases. Functionally, as compared to baseline, most of the patients showed improvements in BCVA of 1 to 2 lines. CONCLUSION: This technique appears to be a safe and effective approach with favourable anatomical and functional results.
Asunto(s)
Retina , Perforaciones de la Retina , Vitrectomía , Humanos , Retina/cirugía , Perforaciones de la Retina/cirugía , Tomografía de Coherencia Óptica , Resultado del Tratamiento , Agudeza VisualRESUMEN
Because neuronal nitric oxide synthase (nNOS) has a well-known impact on arteriolar blood flow in skeletal muscle, we compared the ultrastructure and the hemodynamics of/in the ensuing capillaries in the extensor digitorum longus (EDL) muscle of male nNOS-knockout (KO) mice and wild-type (WT) littermates. The capillary-to-fiber (C/F) ratio (-9.1%) was lower (P ≤ 0.05) in the nNOS-KO mice than in the WT mice, whereas the mean cross-sectional fiber area (-7.8%) and the capillary density (-3.1%) varied only nonsignificantly (P > 0.05). Morphometrical estimation of the area occupied by the capillaries as well as the volume and surface densities of the subcellular compartments differed nonsignificantly (P > 0.05) between the two strains. Intravital microscopy revealed neither the capillary diameter (+3% in nNOS-KO mice vs. WT mice) nor the mean velocity of red blood cells in EDL muscle (+25% in nNOS-KO mice vs. WT mice) to significantly vary (P > 0.05) between the two strains. The calculated shear stress in the capillaries was likewise nonsignificantly different (3.8 ± 2.2 dyn/cm² in nNOS-KO mice and 2.1 ± 2.2 dyn/cm² in WT mice; P > 0.05). The mRNA levels of vascular endothelial growth factor (VEGF)-A were lower in the EDL muscle of nNOS-KO mice than in the WT littermates (-37%; P ≤ 0.05), whereas mRNA levels of VEGF receptor-2 (VEGFR-2) (-11%), hypoxia inducible factor-1α (+9%), fibroblast growth factor-2 (-14%), and thrombospondin-1 (-10%) differed nonsignificantly (P > 0.05). Our findings support the contention that VEGF-A mRNA expression and C/F-ratio but not the ultrastructure or the hemodynamics of/in capillaries in skeletal muscle at basal conditions depend on the expression of nNOS.